Elevator systems



Aug- 22, 1961 D. SANTINI ETAL 2,997,134

ELEvAToR SYSTEMS S|\ E f A" a S /BE om G|\ fF Ben BF g b A'A'A VL V .VIVA

Door Safety lnerlocks /DR Door Safey Interlocks /BDR BJI BD6 /BXZ BWw B23 o n BMZ o c n BUG BW2 BX\ B24 /BMB B'IOT I GD f A'A'A n BRZ BSLHOBI D GD l DBM4 BJ \BJ2 exs INVENTORS gm) Fig-I Danilo Santini and 6./ A George Macreds /f Eydnw ATTORNEY Aug 22, 1961 D. SANTINI ET AL 2,997,134

ELEVATOR SYSTEMS 8d2 BIC BICR Hf /SLHO2 /BSO p a D A'AVA Fig.2

Aug- 22, 1961 D. SANTINI ET A1. 2,997,134

ELEVATOR SYSTEMS AA V Fig. 5

United States Patent() ice ELEVATOR SYSTEMS 1 Danilo Santini, Tenafly, and George Macredis, West Eug'lewood, NJ., assignors to Westinghouse Electric Cor-- poration, East Pittsburgh, Pa., u corporation of Pennsylvania Filed Apr. 7, 1960, Ser. No. 20,712 14 Claims. (Cl. IS7-29) This invention relates to elevator systems and it has particular relation to elevator systems wherein operation is automatically modified to provide different modes of operation.

It is well known that modern elevator systems must have suicient ilexibility to handle various traffic conditions. For example, during a substantial `part of the business day the demand for elevator service in the two di-1 rections of travel generally is substantially balanced. Such periods are known as off-peak periods.

In an oce building, an elevator system may be called upon to handle traic conditions which occur during peak periods wherein large numbers of passengers desire to travel in one direction at substantially'the same time. Such a traffic condition may occur, for instance, at the close of a business day during a "downpeak period when large numbers of elevator passengers desire to proceed downwardly from the higher iioors at approximately the same time. During a down-peak period the elevator cars tend to become fully loaded at the higher iioors of the building. Under' such' circumstances, passengers awaiting service at the lower oors of the building may be kept waiting for unduly long periods of time. Among the solutions proposed for this problem is that taught by the Santini et al. Patent 2,840,189, in which an elevator car under certain conditions is assigned to serve speciiied tloors. Another solution linvolves the division of the oors of a building into zones with one or more elevator cars assigned to provide service primarily for each of the zones. Such operation is well known in the art and has proven to be of material assistance in solving the problems of providing adequatev service during peak periods.

In some heavily populated buildings it has been found desirable to stagger the hours in order to depopulate one door at a time in a predetermined sequence. Such staggered depopulation may occur, for example, during the lunch period. Furthermore, tloors for which staggered depopulation is necessary may be the upper oors of the building. -The passengers from these oors, in accordance with the predetermined sequence, may desire transportation to a lower door on which is located a lounge, to another lower floor on which is located a cafeteria or to the lower terminal or street level oor. In order to meet the requirements of such traffic conditions, the teachings of the above-mentioned Santini et al. patent and zoned down-peak operation may not be the best-solutions.

In accordance with the invention, a structure wherein it is desired to depopulate -oors in a predetermined sequence is provided with an elevator system having means for conditioning the system to furnish special service during such depopulating periods. Although aspects `of the invention are applicable to elevator systems employing only a single car, the invention is particularly .suitable for systemsjemploying a plurality of elevator cars and will be discussed with reference to a multiplecar elevator system. For purposes of illustration,` it will be assumed that during cti-peak periods the elevator :system is conditioned to operate each elevator car on through trips between terminal oors or landings.- A1- lthough suitable dispatchers may be provided for dispatching the elevator cars at predetermined intervals from the terminal floors during off-peak operation, such dispatch- 2,997,134 Patented Aug. 22,

ers are not shown in the illustrated embodiment of the invention in order to simplify the presentation thereof.

During special service operation, successive predetermined groups of elevator cars in the system are assigned to serve successive predetermined floors of the structure for depopulating such floors. In a preferred embodi` ment of the invention, each group of cars is assigned to a given floor for a predetermined assigned period of time. The number of cars in each group and the predetermined' time during which each group of cars serves its assigned floor is based on unloading such floor in a minimum number of trips by its assigned cars. This, in turn, depends upon the potential load at the associated assigned door. ln addition, each group of cars is conditioned to provide service from its assigned oor in only a predetermined direction, for example, the down direction of car travel. Each assigned elevator car is conditioned to by-pass al1 up and down corridor calls for elevator service. Furthermore, each assigned car may be conditioned to respond to car calls for only predetermined floors and to ignore car calls for the remainder of the floors. For example, during special service operation an assigned car may answer car calls for the iioor on which the cafeteria is located and for the lower terminal floor.

During special service operation, elevator cars which are not assigned to predetermined iioors may remain on cti-peak operation, that is, each unassigned car may provide balanced service for all unassigned oors by responding to all corridor calls and to car calls for such oors. Desirably, at least one elevator carin the bank remains conditioned for ofi-peak operation during each period of special service operation. 3 Assuming that it is desired to provide special service operation. tor an assigned iioor in the down direction', an assigned car which is traveling inthe up direction toward its assigned Hor will stop at such oor and will :be conditioned for subsequent travel in the down direction. Concurrently, the doors of the assigned car will opento permit loading of the car. The assigned car will remain at its assigned oor until it is loaded or until the lapse of a-predeterrnined time,.whichever occurs first. The car then will leave the assigned floor to discharge passengers at.` the oor on which the cafeteria is located and/or a the lower terminal floor.

If there `are any passengers in an assigned car at the beginning of an assigned period, the car will answer its y1 registered car call, reverse and by-pass all corridor calls until it arrives at the assigned oor, at which time itis conditioned to receive passengers in the foregoing manner. If, at the beginning of an assigned period of special serv` 'ice operation, an assigned car is traveling in the down direction below its assigned floor, the car will continue to the lower terminal door, reverse, and then proceed to its asigned oor. At the conclusion of special service opera*- tion, i.e., when the last door in the predetermined sequence of oors is depopulated, the entire elevator system reverts to normal or off-peak service.

During special service operation, assigned cars continue to return to `their assigned floor as long as one of the assigned cars leaves suchoor heavily loaded. If no heavily-loaded car leaves the assigned floor Within v a predetermined time, all assigned cars for that floor prefer.'- ably are transferred to off-peak operation until cars are assigned to the next succeding assigned floor.

It will be appreciated that as a result of the special service operation just described, traffic from assigned y floors will be appreciably expedited Without unduly penal,-`

other than an assigned floor during its associated assigned period.

It is, therefore, an object of the invention to provide an elevator system wherein successive predetermined floors of the structure served by the system are substantially depopulated in accordance with a predetermined sequence.

It is another object of the invention to provide special elevator service for a structure having an elevator system comprising a plurality of elevator cars wherein successive predetermined numbers of cars are assigned to provide service from successive predetermined oors of the structure in only a predetermined direction of travel.

It is a further object of the invention to provide an elevator system as set forth in the preceding object wherein at least one elevator car is conditioned to provide balanced service for all unassigned lioors at all times during special service operation.

It is another object of the invention to provide means for starting an assigned elevator car from its assigned oor in the predetermined direction upon the occurrence of a predetermined traffic condition.

It is an additional object of the invention to provide means for starting an assigned elevator car from its assigned lioor in the predetermined direction when such car is heavily loaded or at the lapse of a predetermined time, whichever occurs first.

It is also an object of the invention to provide an elevator system as heretofore set forth wherein all assigned cars are transferred to provide balanced service for all iloors when no heavily-loaded assigned car leaves the associated assigned floor within a predetermined time.

It is still another object of the invention to provide an elevator system as defined in any of the preceding objects wherein an elevator car assigned to provide special service for a floor is conditioned to ignore all corridor calls for elevator service and all car calls for all floors except those car calls registered for a predetermined floor or for predetermined floors which the elevator car may answer when traveling in the predetermined direction.

Other objects of the invention will be apparent from the following description, taken in conjunction with the accompanying drawings, in which:

FIGURE l is a schematic view with circuits shown in straight line form of a portion of an elevator system embodying the invention;

FIGS. 2, 3, 4 and 5 are schematic views with circuits shown in straight line form of further portions of the elevator system illustrated in FIG. l.

In order to facilitate the orderly presentation of the invention, a number of conventions have been adopted. Although the invention may be incorporated in an elevator system having any desired number of elevator cars serving a structure having any desired number of floors or landings, it will be assumed that the invention is incorporated in an elevator system having four elevator cars serving a structure having six floors or landings. The elevator cars are designated by the reference characters A, B, C and D. Inasmuch as the circuits associated with ythe four elevator cars are similar, it will suffice to show primarily the circuits associated with the elevator cars A and B. However, certain components associated with the elevator cars C and D also will be referred to.

Because of the similarity of the circuits and components associated with the four elevator cars, components associated with the elevator cars B, C and D will be identified by the same reference characters employed for the components associated with the elevator car A preceded by the appropriate letter B, C or D. For example, the resistors R4, BR4, CR4 and DR4 are associated respectively with the elevator cars A, B, C and D. Consequently the discussion will be directed primarily to the elevator car A and its circuits.

Relays and switches employed for the elevator system may have front or make contacts and back or break contacts. Front or make contacts of a relay are closed when the relay is energized and picked up. The contacts are open when the relay is deenergized and dropped out. Back or break contacts of a relay are closed when the relay is deenergized and dropped out. The back or break contacts are open when the relay is energized and picked up.

Each set of contacts of a relay or switch is designated by the reference characters employed for the relay or switch followed by a suitable numeral specific to the set of contacts. For example, the reference characters U1 and U3 designate the first and third sets of contacts, respectively, associated with the up switch U or" the elevator car A. In the drawings -all relays are shown deenergized.

In order further to facilitate the presentation of the invention, certain apparatus specific to the car A and certain apparatus common to all of the elevator cars are set forth as follows:

APPARATUS FOR CAR A E-Inductor slowdown relay F--Inductor stopping relay V--Speed relay U-Up switch M--Running relay D-Down switch G-Holding relay W-Up preference relay X--Down preference relay 7 tlT-Non-interference relay DR--Door relay I-Reversing relay K lCR through GCR-Car call registering relays T-Car call stopping relay Sil-Car call relay 78U-Call-above relay S--Floor call stopping relay 78-Call relay SCCO--No car call relay NOX-Assigned lloor relay SLHT-Dispatching timing relay SWR-Auxiliary load relay WST-Load relay tlN-Dispatching relay SLHOB-Car assigning relay APPARATUS COMMON TO ALL CARS lUR through SUR- Up floor call registering relays 2DR through DR-Down floor call registering relays SLHD-Special service master relay CTX--Transfer relay CTA--Timing relay CLT-Notching timing relay N01 through No4- Floor selection relays CNR- Master car assigning relay SWRX-Mastcr load relay FIGURE 1 FIG. l shows the elevator cars A and B and certain control circuits associated therewith. The elevator car A will be assumed to be stopped at the second door of the structure whereas the elevator car B will be assumed to be stopped at the lifth floor of the structure. With these exceptions, the circuits and mechanisms associated with the two elevator cars are similar and will be understood by the reference to those associated with the elevator car A. Circuits `for the elevator car A are shown in the left-hand column of FIG. l, while circuits for the car B are illustrated in the right-hand column thereof.

The elevator car A is connected by a rope or cable 10 to a counterweight 11. The rope 10 passes over a sheave 12, which is secured to a shaft 13- for rotation therewith. The shaft 13 is rotated by a motor 14 which may be of any conventional type. For present purposes it'- 'vvill be assumed that the motor 14 is a direct current tnotor having its armature 14A secured to the shaft 13 and having a eld winding 14-F which is permanently connected across two direct current 'buses L1 and L2 which supply direct current energy for the control circuits.

The elevator car A has therein a plurality of normally-open car-call push-buttons 1c through 6c (FIG. 2) which are actuated for the purpose of registering calls respectively for the first through sixth oors as desired by passengers entering the elevator car.

To permit registration of calls for service by prospective passengers located at the various floors served by the elevator cars, push-button stations are located at such floors. Such a station is shown in FIG. 1 for the third floor. It includes a normally-open up oor call push-button 3U which is pressed by a prospective passenger desiring elevator service in the up direction. A similar pushbutton is located at each floor from whi-ch service in the up direction may be desired. The station also includes a normally-open push-button 3D which is pressed by a prospective passenger desiring elevator service in the down direction. A similar push-button is located at each iloorA from which elevator service in the down direction may be desired. The numeral of the reference characters (as 3D or 3U) indicates the door at which-the pushbutton is located.

The elevator car A also has mounted thereon an inductor slowdown relay E and an inductor stopping relay F which may be of conventional construction. The slowdown relay E has two sets of break contacts E1 and E2 associated therewith. The relay has a normally incompletemagnetic circuit, and initial energization of the winding of the relay alone does not initially open the associated contacts. However, if the slowdown relay E reaches an inductor plate UEP located in the hoistway ofthe elevator car while the winding of the relay is =nergized,-the contacts E1 open. The inductor relay may be of the type which when it opens its contacts maintains the contacts open until the relay winding is deenergized even though the relay passes beyondthe inductor plate. In FIGLI the inductor plate UEP is assumed to be mounted in thehoistway to be reached by the slowdown relay E as the elevator car A nears the third floor. If the elevator car A, duringupftr'avel thereof, is to stop at the third tloor, the winding of the relay E is energized, and, when the relay reaches the inductor plate UEP for the third floor, the contactsEl open to initiate a slow-down operation for the elevator car. It will be understood that a similar inductor plate similarly is associated with each of the oors at which the elevator car A may stop during up travel thereof.

e During down travel of the elevator car A, the inductor relay E cooperates with down inductor plates DEP to initiate a slow-down of the elevator car asit approaches a floor at which the elevator car is intended to stop. For example, if the elevator car is to stop during down travel at the third floor, the winding of the inductor relay E is energized as the elevatorV car nears the third oor. When the inductor relay reaches the down inductor plate DEP for the third iloor, the contacts E2 open to initiate a slow-down operation of the elevator car. It will be understood that a similar inductor plate DEP is provided for each of the iloors at which the elevator car A is to stop during down travel thereof.

The stopping relay F similarly cooperates with inductor plates UFP and DEP for the purpose of bringing the elevator car to a stop as it reaches a door at which it is to stop. Thus, if the elevator car A duringup travel is to stop at the third oor, the winding of the stopping relay F is energized and as the inductor stopping relay F reaches the stopping inductor plate UFP for the third oor, the contacts F1 open. These contacts in opening result in stopping of the elevator car at the third oor. A similar inductor plate is provided for each of the iloors 6 at which the elevator ear A is to stop during up travel thereof.

If the elevator car A is to stop at the third oor during down travel thereof, the winding of the stopping relay is energized, and, as the relay reaches the inductor plate DFP for the third oor, the contacts F2 open to produce a stopping operation of the elevator car at the third floor. It will be understood that a similar inductor plate is provided for each of the oors at which the elevator cai A is to stop during down travel thereof.

Because of the large number of control circuits .required, it is conventional practice to provide each elevator car with a tloor selector 16. This selector includes a plurality of rows of contact segments mounted on an insulating panel 16A. Only two rows of contact segments a1 through a5 and d1 through d5 are illustrated in FIG. 1. The contact segments are successively engaged during travel of the elevator car respectively by brushes aa and dd for the purpose of controlling the energization of certain circuits. For example, if the elevator car A during down travel is to stop at the third floor in response to a car call, the brush aa engages the contact z3 shortly before the elevator car A reaches the third iloor, to initiate a stopping operation thereof. l

The brushes aa and dd are mounted on a brush carriage 16C, which is mounted for movement in accordance with movement of the elevator car, but at a greatly reduced rate. In the embodiment of FIG. 1, it is assumed that the carriage 16C has threaded engagement'with a screw 16S, which is coupled to the shaft 13 throughsuitable gearing for rotation in accordance with of the elevator car A. Consequently, as the elevator car A moves, the brushes mounted on the carriage 16C permit theenergization of appropriate circuits at various pointsof travelofrthe elevator car.

Although the driving motor 14 may be energized 'in various ways, it will be assumed that the control of this motor is ofthe type commonly referred t`o` as'a variable voltage'control. In such a control, a direct current gen.- erator 17 has its armature 17A connected in a vloop with the armature 14A of the motor. A series field winding 17S for the 'generator also may be `included in this loop. The generator has almain eld'winding 17F, which is connectedfor energizationfrom the lbuses L1 and L2 through a reversing switch. This reversing switch includes contacts UZ'and U3 of an up switch. When these contacts are closed, the field winding is energized with proper polarity for up travel of the elevator' car. On the other hand, when contacts D2 and D3 of a down switch are closed, the field winding is energized with proper polarity for down travel of the elevator car. The energization of the iield winding is completed through a resistor R1 for slow-speed operation of the elevator car or through-make contacts V1 of a speed relay for full-speed operation of the elevator car.

The elevator car A is provided with a conventional spring-applied electromagnetically-released brake. This brake includes a brake drum 18D which is secured to the shaft 13 for rotation therewith. A brake shoe 18C normally is biased against the brake drum by means of a spring (not shown). The brake is released upon energization of a brake coil 18B, which cooperates with a magnetic armature 18A secured to the shoe 118C. T'he coil 18B is connected to the buses L1 and L2 for energization either through make contacts U1 or-through make contacts D1 of the up switch AU orthe down switch D. respectively.

The speed relay V is connected for energization from the buses L1 and L2 through either of two paths. One of these paths includes make contacts U4 of the up switch a limit switch 19 and the break contacts E1 of the slowdown relay. The limit switch 19 is cam-operated normally-closed switch which is opened as the elevator car nears itsvupper limit of travel. A

The remaining path of energization comprises the make contacts D4 of the down switch, a limit switch 20 and the break contact E2 of the slowdown relay. The limit switch 20 may be cam-operated. It is normally closed and is opened as the elevator car A nears its lower limit of travel.

.As long as the elevator car A is running, the running relay M is energized. This relay can be energized only as long as the make contacts DR1 of a door relay DR are closed. 'I'he contacts are closed only as long as all of the hoistway doors and car doors for the car A are closed. Such safety provisions are well known in the art.

The running relay M initially can be energized only if the break contacts 70T1 are closed to indicate that a predetermined minimum time has elapsed since the last stop of the elevator car A to permit discharge or entry of passengers and if the make contacts 80N1 of the dispatching relay 80N are closed.

Assuming that the foregoing contacts associated with the running relay M are closed, the relay may be energized initially through either of two paths. One of these paths is as follows:

L1, 80N1, 70T1, W1, F1, 21, U, M, DRI, L2

Since the up switch U is energized through this path, it follows that the elevator car will be conditioned for up travel. The limit switch Z1 is a normally-closed mechanically-operated switch which is opened as the elevator car A nears its upper limit of travel. When energized, the up switch U closes ,its make contacts U5 to establish aholding circuit around the contacts 80Nl, 70T1, and W1.

The second path for initially energizing the running relay M may be traced as follows:

L1, 80N1, 70T1, X1, F2, 22, D, M, DRI, L2

Since the down switch D now is energized, it follows that the elevator car A is conditioned for down travel. The limit switch 22 is a mechanically-operated normally-closed switch which is opened as the elevator car A nears its lower limit of travel. When it picks up, the down switch D closes its make contacts D5 to establish a holding circuit around the contacts 80N1, 70T1 and X1.

I=f the elevator car A is to be operated by a car attendant, the contacts 80N1 and 70"I`i1 may replaced by a manually-operated switch which is closed by the car attendant when the car is to be moved Ifrom a oor at which it is stopped. However, in a preferred embodiment of the invention, the automatically-operated contacts 80N1 and 70T1 are employed.

The inductor slowdown relay E, the inductor stopping relay F and a holding relay G are energized in parallel from the buses L1 and L2 through the make contacts M1 ofthe running relay M. To complete an energizing circuit for these relays E, F and G, one of the following conditions must be present: first, the make contacts T1 lare closed to indicate that a car call is registered for a oor which the` elevator car A is approaching. Second, the make contacts S1 are closed to indicate that the elevator car A is conditioned to stop` at a lioor in answer to -a registered oor call for such floor.

When the holding relay G is energized, it closes its make contacts G1 to establish with the make contacts M1 a holding circuit `for the inductor relays E and F.

The door relay DR is connected across the buses L1 and L2 through door safety interlock contacts respectively operated by each door associated with the elevator car A. If any of the doors is open, the contacts associated therewith also are open to prevent energization of the door relay DR.

The direction of travel of the elevator car A is determined initially by an up preference relay W and a down preference relay X. For the up preference relay W to be energized, the break contacts D6 must be closed (ie. the down switch D is energized) and the break contacts X2. must be closed (ie. the down preference relay X is deenergized). The limit switch 2'3 also must be closed. This switch is normally closed and is opened as the elevator car A reaches its upper limit of travel, in this case the sixth floor.

Energization of the up preference relay W also requires closure of at least one of two sets` of contacts. These include the break contacts J1, which are closed when the elevator car A is not conditioned to reverse at the nearest floor in its direction of travel. Make contacts M2 are closed as long as the elevator car A is running.

The down preference relay X is energized if the break contacts U6 are closed (i.e. the up switch U is deenergized), the break contacts W2 are closed (ie. the up preference `relay is deenergized) and the limit switch 24 is closed. This limit switch is normally closed and is opened as the elevator car A reaches the lower terminal floor.

As long as the elevator car A is running, the make contacts M3 are closed to energize the non-interference relay 70T. When the elevator car A stops, the contacts M3 open to deenergize the relay. However, the relay 70T has a substantial delay in dropout. This delay may be provided in any suitable manner, as by connecting a resistor R2 across the relay coil. The time delay in dropout is selected to be suicient to permit discharge of passengers from the elevator car A or entry of .passengers into the elevator car A after each stop.

Energization of the high call reversal relay J prepares the elevator car A to reverse during up travel at the nearest floor. The relay J may be energized if the elevator car A is conditioned for up travel (break contacts X3 are closed) or if the break contacts M4 are closed to indicate that the elevator car A is not running, if the make contacts SLHOBI are closed to indicate that the car A is conditioned for special service operation and if the make contacts 78U1 are closed to indicate that no higher calls remain to be answered (in some cases no higher car calls).

When the reversing relay I is energized, its make contacts J2 close to establish a holding circuit therefor through the break contacts X3 or M4.

FIGURE 2 FIG. 2 shows the car call registration circuits `for the elevator cars A and B and the circuits for energization of their respective car call relays 50 and B50.

It will be recalled that the elevator car A is provided with a plurality of push-buttons 1c through 6c for the purpose of registering car calls. Each of these pushbuttons has associated therewith a car call registering relay ICR through GCR, respectively. The push-buttons and call registering relays cooperate with `four rows of contact segments located on the floor selector for the elevator car A. The contact segments a1 through a5 cooperate with the brush aa for the purpose o-f initiating a stopping operation of the elevator car during down travel of the elevator car respectively at the iirst through iifth floors. The contact segments b2 through b6 cooperate with a brush bb for the purpose of initiating a stopping operation of the elevator car during up travel of the elevator car respectively at the second through sixth tloors. A brush cc cooperates with a row of contact segments c2 through c6 and a brush dd cooperates with a row of contact segments d1 through d5 Ifor the purpose of cancelling registered car calls as they are answered respectively during down travel and up travel of the elevator car. It will be understood that for each contact segment the numeral of the reference character designates the oor with which the contact segment is associated. Thus, the reference character a1 designates the contact segment for the first iloor in t-he a row.

Assuming that the elevator car A is not conditioned to provide special service and that the no car call relay SCCO, therefore, is deenergized, by reference to FIG. 2 it will be observed that when the car call push-button Sc is pressed the car call registering relay SCR isv connected therethrough and through break contacts SCCO3 across the buses L1 and L2. This relay closes its make contacts SCR1 to establish a holding `circuit around the push-button and the contacts SCCO3. The contact segments a and b5 then are connected through the contacts SCRl to the bus L1.

If the elevator car A is set for down travel, the marke contacts X4 are closed; and if the elevator car is approaching the fth oor, the make contacts M5 of the running relay also are closed. Consequently, as the elevator car nears the fifth tloor the brush aa engages the contact segment a5 to complete the following energizing circuit for the car call stopping relay T:

L1, SCR1, aS, aa, X4, T, MS, L2

L1, SCRl, SCRN, c5, cc, XS, M6, L2

The operating coil of the registering relay SCR and the cancelling coil SCRN are wound in opposition on a com mon core. Consequently, energization of the cancelling coil SCRN cancels the eiect of the operating coil and resets the registering relay SCR. Preferably, as the elevator car stops at the fth oor, theI Abrush aa passes slightly below the associated contact segment a5; however, the brush cc remains in engagement with the associated contact segment c5 as long as the elevator car A remains at the floor.

' Next it will be assumed that the same call is registered for the fifth floor as the elevator car A travels up toward the fifth iloor. Under these circumstances, the make contacts W4 and WS'of -the up preference relay Vare closed. As the elevator car A nears the-fifth tloor, the brush bb engages the contact segment bS to complete the following circuit:

L1, SCRL bS, bb, W4, T, MS, LZ

Ihe energization of the car call -stopping relay T results The energization of the cancelling coil SCRN resets the :all registering relay SCR. During the stopping operation, the brush bb preferably passes slightly above the issociated contact segment b5, Whereas the brush dd renains in engagement with the associated contact `seg- :nent d5 as long as the elevator car A is at the fifth nediate oors are similar to those described for the fifth loor. It will be noted, however, that break contacts N3 of the up preference relay W parallel break contacts CCO8 in the circuit of the second tloor ca'r call registerng relay ZCR. The eilect of these contacts on operation' )f the car A will be discussed hereinafterin the sec-4 ion entitled, Special Service Operation.

` The car call registering circuits for the upper terminal -fsixth oor) may be similar to those employed for the nterrnediate floors. However, since the elevator car A `tops at the sixth iioor only during up travel, contact segnents for the sixth oor need not be provided in the a ind d rows. By reference to FIG. 2, it will -be noted ,that

`The carl call registering circuits for all of lthe inter-A 10 only contact segments b6 and c6 are provided for-th sixth floor. i

The car call registering circuits for the lower terminal or rst floor may `be similar to those provided for the intermediate floors. Since the elevator car stops at the rst floor only during down travel, contact segments for the first floor need not be provided in the b and cv rows: For this reason, in the car call registering circuits only contact segments a1 and d1 are illustrated for the rst oor. Since the car A always must stop at the first floor during down travel thereof, the contact segment a1 is connected permanently to the bus L1 to insure energiza tion of the relay T and a resulting stopping operationofthe car during such travel.

It Will be observed in FIG. 2 that contacts of the no car call relay SCCO and of the lloor selection relays: N01 through N04 are associated with some of the car call registering circuits for the elevator cars A and B butv not with other car call registering circuits thereof. The operation of these contacts will be discussed hereinafter in the section entitled, Special Service Operation. i

The lower part of FIG. 2 illustrates circuits associa-`- ted with the car call relays S0 and B50. In order fol`v these relays to be energized, make contacts SLHOI and.

SLHOZ, respectively, must be closed to indicate that the special service master relay SLHO is energized land. picked up. In series with the relay 50 for the car A are parallel make contacts 1CR2 through 6CR2 of the cari call registering relays ICR through 6CR, respectively.. Thus, if a car call is registered for the car A, closure vof the corresponding set of make contacts ICRZ through 6CR2 results in energization of the car call relay 50,; provided the contacts SLHOI also are closed. closure of additional contacts upon the registration ofi additional car calls for the car A merely provides ad ditional paths for energization of the relay S0. It will be apparent that the relay 50, once energized, cannotdrop out until all of the car calls registered for the elefvator car A are answered by the car A. The car calll relay B50 operates similarly in response tothe registra,

tion of car calls for the car B.

FIGURE s i' The upper part of FIG. 3 illustrates up oor call--Y These circuitsV registering circuits for the elevator cars. are operated by means of normally-open push-buttons 11U through 5U common to all of the elevator carsand located respectively at the rst through fth lioors. The push-buttons have associated therewith up floor call` registering relays IUR through SUR and cancelling coils' lURN through SURN in a manner which will be clear- A brush ff cooperates with a row of contact segments4 f1 through f5, respectively for the rst to fth floors for the elevator lcar A.

Let it be assumed that while the elevator car A" is closes its rnake contact SURI to establish a holding circuit around the push button.

Since the elevator car is assumed to be traveling up;- `the make contacts W6 and W7 of the up preference relay,

assigned to provide special service. As the elevator Thel A nears the iifth oor, the brush ee engages the contact segment e to complete the following circuit:

\L1, SURI, e5, ee, W6, S, SLHOBZ, L2

The energization of the iioor call stopping relay S initiates the stop at the iifth iioor. dn response to movement of the car toward the iifth iloor, the brush ff engages its contact segment f5. As slowdown of the elevator car is initiated, the break contacts V2 close to complete the following cancelling circuit:

L1, EURL SURN, f5, ff, W7, SLHOB 3, V2, L2

This resets the up oor car registering relay SUR. As the elevator car A comes to a stop, the brush ee preferably passes slightly above Ithe contact segment e5. However, the brush ff remains in engagement with the contact segment f5 as long as the elevator car A remains at the fifth iioor.

'By inspection of FIG. 3, it will be observed that the contact segment e5 is connected to corresponding contact segments for the other elevator cars in the bank (such -as contact segment BeS for the eelvator car B). Similarly, the contact segment f5 is connected to corresponding contact segments (such as the contact segment BS) for the remaining cars of the bank. Consequently, operation of the push button 5U is elective to stop the first up-traveling elevator car which reaches the fifth floor and which is conditioned to accept the call at the fifth As will ybe observed in FIG. 3, the up floor call registering circuits for all of the intermediate iioors are similar. During up travel, the elevator cars always must stop iat the sixth floor if they reach such floor. For this reason, n single contact segment e6 for the car A suiices for the sixth floor and is connected permanently to the bus L1. Since the elevator car A does not stop during up travel at the lower terminal or first oor a contact segment in the e row is not required for the rst iioor. With these exceptions, the call registering circuits for the iirst and sixth oors are similar to those described for the fth oor.

The lower part of FIG. 3 illustrates the down floor call registering circuit for the elevator cars. IDown floor calls are registered by operation of normally-open push buttons 2D through 6D for the second through sixth iioors, respectively, and have associated therewith down iioor call registering relays 2DR through 6DR and cancelling coils ZDRN through GDRN. Each push button cooperates with its call registering relay and its cancelling coil in the manner discussed with reference to the up oor call push buttons. For the elevator car A, a row of contact segments Ig1 through g5 cooperates with a brush gg, a row of contact segments h3 through h6 cooperates with a brush hh, and a row of contact segments i2 through i6' cooperates with a brush if.

Let it be assumed that the elevator car A while traveling down is approaching the fourth iioor, at which a down floor call has been registered by operation of the push button 4D. iSuch operation resul-ts in energization of the down oor call registering relay 4DR to close the make contacts 4DR1. Since the elevator car is traveling down, the make contacts X6, X7 and 70T2 are closed. It will be assumed that the break contacts SLHOBZ and SLHOB3 are closed.

As the elevator car A nears the fourth floor, the brush gg engages the contact segment g4 to complete the following circuit:

The energization of the iloor call stopping relay S initiates a stopping operation of the elevator car A at the fourth floor.

As the elevator car continues its approach the brush hh engages -the Contact segment h4 and the brush ij engages the contact segment i4. The initiation of slow- 12 down ofthe elevator car A results in closure of the break contacts V2 to complete the following cancelling circuits:

L1, 4DR1, 4DRN, h4, hh, 70T2, SLHOB3, V2, L2. L1, 4DR1, 4DRN, NO2-3 and 'CT X3 in parallel i4, X7, SLHOBS, V2, L2

The energization of the cancelling coil resets the call registering relay 4DR. Preferably, as the elevator car A comes to a stop, the brush gg passes slightly below the associated contact segment g4, but the brushes hh and ji remain in engagement with their respective associated contact segments h4 `and i4.

The contact segment g4 is connected to corresponding contact segments (such as the contact segments Bg4) of the remaining cars, and the contact segment h4 is connected to corresponding contact segments (such as the contact segment Bh4) of the remaining oars. Similarly, the contact segment j4 is connected to `corresponding contact segments (such as the contact segment Bj4) for the remaining cars. Consequently, the iirst elevator car to approach the fourth iioor while traveling down will answer a call registered by the call registering relay 4DR.

The down iioor call registering circuits for all of the intermediate oors are similar and may be traced readily in FIG. 3. (It will be observed that the down oor call registering circuit for the second iioor has no contact segment in the h row Iand that the contact segments i2 and BjZ are connected directly to the cancelling coil ZDRN. For purposes of the present discussion, these differences are immaterial and the reasons therefor will be readily understood from the description of special service oper-ation hereinafter.) The `down oor call registering relay circuit for the upper terminal or sixth oor also may be similar. However, since the elevator car A does not stop at the sixth floor during down travel, the contact segment in the g row may be omitted for the sixth floor. Since the elevator car A always must stop at the lower terminal floor, a single rst oor contact segment g1 may be provided for the elevator car A for the first floor, and this contact .segment may be connected permanently to the bus L1.

FIGURE 4 lu FIG. 4 a call circuit 30 for car A is provided which has two functions. This circuit energizes 4a call relay 7-8 when no call is registered by operation of the car call push buttons for the elevator car A and by any floor call push button. "In addition, the call circuit 30 energizes the call-above relay 78U as the elevator car during up travel thereof nears the highest oor for which a down floor call or a car call is registered provided no up floor call is registered for such floor or for a higher door.

The call circuit 30 includes break contacts for all of the floor call registering relays and for all of the elevator car A car call registering relays arranged in the order of the oors. This circuit may be traced as follows:

L1, 6CR3, GDRZ, SURZ, SCRS, `SDRZ, 4UR2, 4CR3, 4DR2, SURZ, SCRS, SDRZ, ZURZ, 2DR`2, 2CR3, 1CR3, 1UR2, 78, LZ

By inspection of this circuit, it will be observed that as long as a call is registered by operation of the car call push buttons for the elevator car A or the floor call push buttons the relay 78 is deenergized.

The call circuit 30 has associated therewith a row of contact segments k2 through k6 `which are engaged successively by the brush kk as the elevator car A moves. The contact segments k2 through cS for the second through `fifth floors, respectively, are so located relative to the call circuit 30 that each contact segment is placed below all break contacts of the call circuit which require travel of the elevator car A above such contact segment. Thus, the contact segment kS is connected to the call circuit between the contacts 5UR2 and SCRS. The contact segment k4 is connected between the contacts 4UR2 and 4CR3. The location of the remaining intermediate floor 13 contact segments similarly may be ascertained by reference to FIG. 4. It will be noted that the contact segment k6 is connected directly to the bus L2 and that the relay 78U is connected between the brush kk and the bus L2 through make contacts W8 of the up preference relay W.

IIn certain cases, it is desirable to prevent registered calls from affecting the call circuit 30. For example, it may be desirable under some conditions to prevent registered oor calls from affecting the operation of the relays 78U and 78. To this end, make contacts of the car assigning relay SLHOB are provided for the purpose of shunting the break contacts of the oor call relays for floors above the iirst floor. When the relay SLHOB is energized, the contacts SLHOB4 through SLHOB7 close to shunt the break contacts SURZ through ZURZ and 6DR2 through ZDRZ.

FIG. 4 also illustrates circuits associated with special service operation of the elevator cars A and B. If the elevator car A is assigned to special service operation, the make contacts SLHOB8 are closed. In order for the no car call relay SCCO to be energized, the break contacts 70T3 must be closed to indicate that the noninterference relay 70T has dropped out, and the break contacts 50-1 rnust be closed to indicate that no car call remains to be answered by the elevator car A. Pickup of the relay SCCO` is accompanied by closure of its make contacts SCCO9 to establish a holding circuit for the relay. Thus, once the relay SCCO is energized, it remains picked up through its holding contacts SCCO9 and through the make contacts SLHOB8 as long as the elevator car A is assigned to special service operation.

The assigned iioor relay NOX for the elevator car A is associated with a row of contact segments m3, m4 and m6, which are engaged successively by a brush mm as the elevator car A moves. The contact segments m3, m4 and m6 are associated, respectively, with the third, fourth and sixth floors, the contact segments being connected to the bus L1 through respective make contacts NO3-3, NO2-4 and NOI-4. If the elevator car A is assigned to provide special service, one of the latter sets of contacts will be closed.- Assume, for example, that the car A is assigned to provide special service for the sixth iloor. As the car A arrives at the sixth iloor, the brush mm engages the contact segment m6 to establish the following circuit:

L1, NOI-4, m6, mm, NOX, SLHOB3, L2

Energization of the relay NOX is accompanied by closure of its make contacts NOXl. lf the non-interference relay 70T has dropped out to close its break contacts 70T4, a holding circuit through the contacts 70T4 and NOXl is established for the relay NOX.

It will be observed that the assigned iloor relay BNOX for the elevator car B also has a brush and a row of contact segments associated therewith. 'In the case of the elevator car B, however, the contact segments Bind, BmS and Bm6 are provided for the fourth, fifth and sixth doors, respectively. The reasons for the differences in the contact segments in the m rows for the cars A and B will be apparent from the description of operation hereinafter.

As long as the make contacts SLHOBS are closed and non-interference relay 70T for the elevator car A remains picked up to maintain its make contacts 70T5 in closed condition, the dispatching timing relay SLHT is energized. When the non-interference relay times out, the contacts 70T5 open to deenergize the relay SLHT. However, the relay SLHT has a substantial delay in dropout. This delay may be provided in any suitable manner, as by connecting a resistor R3 across the relay coil. The time delay in dropout is selected to be sufficient to permit the entry of a relatively large number of passengers into the elevator car A at an assigned oor. In a preferred embodiment of the invention, the time delay may be of the order of 15 seconds.

Energization of the auxiliary load relay SWR indicates that the elevator car A is at its assigned oor (make contacts NOXZ are closed), that the elevator car A is loaded (break contacts W5T1 are closed) and that all of the doors associated with the elevator car A are closed (make contacts DRZ are closed). Thus, pickup of the relay SWR signifies that the car A is loaded and is about to leave its assigned lioor.

Energization of the load relay WST is controlled by a load weighing switch WH. When sufficient load has entered the elevator car, the switch WH opens to drop out the relay WST. Such switches are well known in the art.- The switch WH may be adjusted to open when the elevator car A is approximately fully loaded. Desirably, the relay WST is provided with a short time delay in dropout such as one second. This delay may be provided in any suitable manner as by connecting a resistor R4 across the relay coil.

The dispatching relay 80N may be energized if one of the following conditions is present: First, the break contacts 78-1 are closed to indicate that a call for service which may be answered by the car A has been registered, and the break contacts SCCO10 are closed to indicate that the elevator car A is not conditioned for special service operation. Second, the break contacts J3 are closed to indicate the elevator car A is not condi'- tioned to reverse at the next floor reached by the elevator car or at the lioor at which it is stopped (with the excep'- tion of the lower terminal floor) and the make contacts SCCO11 are closed to indicate that the car A is conditioned for special service operation. Third, the make contacts J 4 are closed to indicate that the elevator car A is conditioned to reverse at the next floor reached by the elevator car during up travel thereof or at the iioor at which it is stopped (with the exception of the lower terminal floor). Y

Additionally, in order for the relay 80N to be energized, one of the following conditions must be satisfied: If the car A is located at an assigned iioor during special service operation and if the dispatching time for the car has expired, the break contacts SLHTI are closed. If the car A is loaded during special service operation the break contacts W5T2 are closed. lf the car A is not located at an assigned oor during special service operation, the break contacts NOX3 are closed. Finally, if the no car call relay SCCO for the car A is dropped out, its break contacts SCCO12 are closed. Pickup of the relay 80N results in the starting of the elevator car A from a floor at which it has stopped both during oit-peak operation and during special service operation.

When the elevator system is conditioned to provide special service operation, it may be desirable to provide suitable information for system passengers, For example, `during such operation an assigned elevator car does not provide up service. A sign may be operated at each oor to present such information to system passengers. In FIG. 4 such signs 101 are connected between the buses L1 and L2 through make contacts SLHOB9 of the car assigning relay SLHOB. The signs 101 conveniently may be located adjacent the elevator car A at the various oors of the building.

FIGURE 5 FIG. 5 illustrates apparatus common to the elevator cars A, B and C for special service operation.

A master clock 1BM and a one-half hour clock IBI-I are connected directly across the buses L1 `and L2. The master clock 1BM is a twenty-four hour clock which has a set of contacts that close to initiate special service operation and that open shortly thereafter. The one-half hour clock has make contacts which close and break contacts which open for a period of approximately two minutes at the start of each of a plurality of special service assignment periods. Since the special service operation described herein is particularly suitable for lunch hour periods, it will be assumed that the master clock 1BM has make contacts which close at 11:14 a.m. and' 15 `that the one-half hour clock has make contacts which close and break contacts which open for approximately two minutes at each of the following times: 11:15 am.; 11:25 am.; 11:31 am.; 11.35 am.; and 11:42 am. Such clocks are well known in the art, and it appears unnecessary to describe them further.

Assuming that a manually-operable switch 103 is in closed condition, the special service master relay SLHO initially is energized through closure of the make contacts 1BM1 of the master clock IBM in series with parallel break contacts NOd-4 and 61-1. Pickup of the relay SLI-IO is accompanied by closure of its make contacts SLHO3 to establish a holding circuit for the relay through the aforementioned parallel contacts. At the termination of special service operation, the contacts No4-4 and 611 simultaneously open to drop out the Special service master relay SLHO. The switch 103 is provided in the event that it is desired to prevent the elevator system from providing special service operation. On weekends, for example, when the building is lightly populated, the switch 103 may be placed in open condition. It will be assumed for purposes of the present discussion, however, that the switch 103 is in closed condition.

Energization of the relay SLHO also is accompanied by closure of its make contacts SLHO4 to provide direct current energization for the bus LZA and thus for the circuits of FIG. 5 below these contacts. For the remainder of the discussion of FIG. 5, it will he assumed that the relay SLHO is energized and, therefore, that its make contacts SLHO4 are closed.

Energization of the transfer relay CTX signiiies that heavy demand for down service from an assigned iloor has terminated before the end of the associated assigned period of special service operation. Pickup of the relay CTX initially is effected through series make contacts CTAl and SWRXI. When the relay CTX picks up, a holding circuit is established therefor through its make contacts CTXS and through a plurality of break contacts of the floor selection relays N01 through N04, as will be apparent from inspection of FIG. 5. Subsequent dropout of the relay CTX may occur under any one of the following conditions: the parallel break contacts NOI-6 and NO2-6 open simultaneously at the termination of the rst assigned period of special service operation; the parallel break contacts NO2-7 and NO3-4 open simultaneously at the termination of the second assigned period of special service operation; the parallel break contacts NO3-5 and NO4-5 open simultaneously at the end of the third assigned period of special service operation or the make contacts SLHO4 open at the end of the fourth assigned period of special service operation.

Energization of the individual car assigning relays SLHOB, BSLHO'B and CSLHOB initially is controlled by make contacts CNRI of the master car assigning relay CNR. If the contacts CNRl are closed, energization of the individual car assigning relays is further controlled by contacts of the oor selection relays NO2 through N04. Thus, if the contacts CNRI are in closed condition, the car assigning relay SLHOB for the elevator car A may be energized for all assigned periods of special service operation except the fourth period, when the break contacts NO4-6 are open; the car assigning relay BSLHOB for the elevator car B may be energized for all assigned periods of special service operation except the third period, when the break contacts NO3-6 are open; and the car assigning relay CSLHOB for the elevator car C may be energized for all assigned periods of special service operation except the second and third periods, when the break contacts NO2-8 and NO3-7, respectively, are open.

The timing relay CTA may be of any suitable construction capable of providing the desired timing operation.` In the embodiment illustrated in FIG. 5, the relay is controlled electronically by circuits including an electronic device such as a tube TU1. This tube may be of 16 any suitable type and may be either of the high-vacuum or gaseous-discharge type In a preferred embodiment of the invention, the tube TU1 is a gaseous-discharge tube of the type known as thyratron. This thyratron maybe either of the cold cathode or of the hot cathode type.

The tube TU1 has a plate electrode 310:, a cathode electrode 311, and a control or grid electrode 312. The voltage between the grid and cathode electrodes is determined by a capacitor CA1. The capacitor is discharged through a path which includes a resistor R5 and either make contacts SWR2, BSWRZ or CSWRZ of the respective auxiliary load relays of the elevator cars A, B and `C or break contacts CNRS of the master car assigning relay CNR.

Wlien the capacitor CAI is to be charged, it is connected across the buses L1 and L2 through a circuit which includes a resistor R6, break contacts CSWRI, BSWR1 and SWR1 and make contacts CNR2. The bus L1 may represent the positive terminal of the direct current source of electrical energy.

When the tube TU1 lires or has a discharge initiated between the plate and cathode electrodes, the timing relay CTA picks up and closes its make contacts CTAZ to establish a holding circuit around the tube TU1 through a resistor R7. Closure of the contacts CTAZ also results in the shunting of the plate and cathode electrodes of the tube by the resistor R7 to terminate the discharge in the tube.

The operation of the timing relay CTA now will be considered in detail. It will be assumed initially that the master car assigning relay CNR has picked up to close its make contacts CNRZ and to open its break contacts CNR3. Immediately prior to such operation, the timing relay CTA was deenergized. Opening of the contacts CNR3 interrupts the discharge circuit for the capacitor CAI, since under the assumed conditions the parallel make contacts SWR2, BSWRZ and CSWRZ also are open.

Closure of the make contacts CNR2 results in completion of the following charging circuit for the capacitor CAI:

L1, CNR2, SWR1, BSWR1, CSWRI, R6, CAI, L2

The capacitor CAI now starts to charge at a rate determined by the resistance and the capacitance of the charging circuit.

Upon expiration of the time required for the voltage across the capacitor CA1 to build up to a suitable value, the tube TU1 fires to establish the following energizing circuit for the timing relay CTA:

L1, CNRZ, SWR1, BSWRl, CSWRI, CTA, 310, 311, L2

If desired, the resistor R6 may have an adjustable resistance or the capacitor CA1 may have an adjustable capacitance, or both may be adjustable for the purpose of adjusting the time delay in pickup of the relay CTA.

`In picking up the relay CTA closes its make cont-acts CTA2 to establish a holding circuit around the tube TU1 through the resistor R7. Inasmuch as the contacts CT' A2 and the resistor R7 shunt the plate and cathode electrodes of the tube TU1, the discharge between such electrodes is terminated.

Although the speciiic time delay in pickup of the relay CTA will depend upon the requirements of each specific elevator installation, it will be assumed in the present system that the relay CTA is `designed to pick up with a time delay of the order of seconds.

Let it be assumed in the preceding example that after the relay CNR picks up to close its make contacts CNRZ to initiate the charging of the capacitor CA1, the relay SWR picks up to open its break contacts SWR1. and to close its make contacts SWR2 before the capacitor CAI charges sufficiently to initiate a firing of the tube TU1, i.e., before the expiration of 90 seconds after the closure of the make contacts CNRZ. Opening of the contacts SWR1 interrupts the charging circuit of the capacitor CA1, while closure of the make contacts SWR2 establishes a discharge path for the capacitor CA1 through the resistor RS. Thus, as long as at least one of the auxiliary load relays SWR, BSWR or CSWR picks up before the expiration of the 90 second period, the timing relay CTA is prevented from picking up. Subsequent dropout of the auxiliary load relay results in the initiation of a timing operation of the timing relay CTA.

Operation of the notching relays 61 and 62, the notching timing relay CLT, the iioor selection relays N01 through N04 and the master car assigning relay CNR now will be described.

Assuming that the manually operated switch 103 is in closed condition, at 11:14 am., as heretofore noted, the special service master relay SLHO will pick up through the make contacts 1BM1 of the master clock 1BM to close the make contacts SLHO4 to provide direct current energization for the circuits of FIG. 5 connected to the bus LZA below these contacts. Closure of the make contacts SLI-TO3 results in the establishment of a holding circuit for the special service master relay SLI-IO. (lt will be recalled that the make contacts 1BM1 reopen after the expiration of a relatively short time interval.)

When the make contacts SLHO4 close, the notching timing relay CLT is energized through the closed break contacts 1BH2 on the one-half hour clock BH. Closure of the make contacts CLT1 has no immediate effect on operation, since the make contacts 1BH1 in series therewith are open.

It will be -recalled that at 11:15 am. the one-halt` hour clock 1BH operates its make contacts 1BH1 and its break contacts IBI-12. Opening of the contacts `1BH2 has no immediate effect on operation, since the notching timing relay CLT has a substantial delay in dropout. The delay may be provided in any suitable manner, as by connecting a resistor R9 across the relay coil. The time delay in dropout is selected to be sufficient to permit certain operations to occur prior to such dropout, as will be apparent from the following discussion.

Closure of the make contacts 1BH1 results in energization of the notching relay 61 through the following circuit:

L1, 62-1, CLT1, IBI-I1, 62-3, 61, R8, LZA

The resistor R8 has a resistance of a value sufficient to limit current flowing through the relay 61 to a safe magnitude.

Opening of the break contacts 61-1 -in the circuit of the special service master relay SLHO has no immediate effect on operation, since the break contacts NO-4 in parallel therewith remain closed. Closure of the make contacts 61-2 also has no immediate elfect on operation, since such closure merely establishes a short circuit around the notching relay 62, as follows:

The ymake contacts 61-3 close to establish the following energizing circuit for the floor selection relay N01:

Opening of the break contacts 61-4 and 61-7 and closure ofthe make contacts 61-5 have no immediate effect on circuit operation. The make contacts 61-6 close to establish a holding circuit for the iioor selection relay NOI through its now closed holding contacts NOI-8.

Turning now to the remaining contacts of the floor selection relay N01, opening of its break contacts NOI-6 has no effect on operation, since the break contacts NO2-6 in parallel therewith remain closed. Closure of the make contacts NOI-7 has no immediate eifect on operation, since the make contacts 6-1-3 in parallel therewith are closed, as aforementioned. Closure of the make contacts NO1-9 also has no effect on operation, since the `break contacts in series therewith 61-4 now are open. Assuming that the break contacts CTX6 are closed, closure of the make contacts NOI-10 results in pickup of the master car assigning relay CNR.

Closure of the make contacts CNRI results in pickup of the individual car assigning relays SLHOB, BSLHOB and CSLHOB, since the respective break contacts of the licor selection relays in series therewith all remain closed at this time. Closure of the make contacts CNR2 initiates a timing operation of the timing relay CTA, while opening of the break contacts CNRS interrupts the discharge circuit for the capacitor CA1.

After a time sufficient to insure the completion of the above sequence of operations, the notching timing relay CLT times out. Opening of the make contacts CLT1 removes the short circuit around the notching relay 62, which picks up through the following energizing circuit:

It will be observed that the notching relay 61 remains energized in series with the notching relay 62. Opening of the break contacts 62-1, 62--3, and 62-6 and closure of the make contacts 62-2 and 62--4 have no immediate effect on operation. The make contacts 62-5 close to parallel the now closed make contacts 61-6, thus having no effect on operation.

As mentioned heretofore, the one-half hour clock 1BH operates to reopen its make contacts 1BH1 and to reclose its break contacts IBI-l2 after a period of approximately two minutes from the respective closure and opening thereof. Thus, at 11:17 aim. the make contacts 1BH1 open without immediately effecting operation, and the :break contacts 1BH2 close to reenergize the notching timing relay CLT. (This two-minute period of operation of the contacts of the one-half hour clock 1BH may vary slightly depending upon conditions; but in any event, the length of the period should be sufficient to insure the foregoing sequence cf operations before the contacts 1BH1 reopen and the contacts 1BH2 reclose). As a result of the pickup of the relay CLT, its make contacts CLT1 close but have no effect on operation, since the make contacts `1BH1 now are open. Thus, the oor selection relay N01 remains picked up for the rst assigned period of special service operation, that is, until 11:25 am., when the contacts of the one-half hour clock IBH again operate to produce the following sequence of operations. The break contacts IBHZ open to initiate the timing out of the notching timing relay CLT, and the make contacts 1BH1 close to establish the following short circuit -around the notching relay 61:

Thus, the notching relay 61, as a result of the short circuit therearound, drops out.

Closure of the break contacts 61-1 has no effect on operation, since the break contacts NO4-4 in parallel therewith also are closed. Opening of the make contacts 61-2 also has no effect on operation, since the notching relay 62 remains energized through the following holding circuit:

L1, 62, 62-2, 1BH1, CLT1, 62,-#4, R8, LZA

Opening of the make contacts 61-3 has no effect on operation for the reason that the make contacts NOI-7 now are closed. Closure of the break contacts 61-4 resuits in energization of the floor selection relay NO2 through the now closed contacts NO1-9 (closure of the contacts 61-4 has no effect on the floor selection relay N04, since the make contacts NO3-10 in series therewith are open). Opening of the make contacts 61-5 has no immediate effect on operation. Opening of the make contacts 61*6 also has no effect on operation, since the make contacts 62-5 in parallel therewith now are closed. Closure of the break contacts y61--7' results in the establishment of a holding circuit for the oor selection relay NO2 through its make contacts ,NO2-10, since the relay NO2 now is picked up.

Turning now to operation of the remaining contacts of 19 the relay NO2, it will be observed that both of the break contacts NO1-6 and NO2-6 now are open to interrupt the holding circuit of the transfer relay CTX. Such interruption would result in dropout of the relay CTX if it be assumed that the relay was energized through its holding contcats CTXS. (Such dropout would result in the closure of the break contacts CTX6 to reenergize the master car assigning relay CNR through the now closed parallel make contacts NOll-ltl and NO2-12). Opening of the break contacts NO2-7 has no effect on operation at this time, since the break contacts NO3-t in parallel therewith remain closed.

Opening of the break contacts NO2-8 results in dropout of the car assigning relay CSLHOB for the elevator car C, assuming that the make contacts CNRll are closed. The break contacts NO2-9 open to interrupt one of the holding circuits for the tloor selection relay N01, but the relay N01 still is maintained energized through its remaining holding circuit comprising the make contacts NOI-8 and S12- 5. The make contacts NOll-ltl close to establish a holding circuit for the relay NO2 through the break contacts 61-7. (It will be recalled that the notching relay 61 now is dropped out.) Closure of the make contacts NO211 has no immediate effect on operation, since the make contacts 61-5 in series therewith now are open. As mentioned above, the make contacts NO2-12 close to parallel the Still closed make contacts NOI-ii?, thus having no immediate effect on operation.

Next it will be assumed that sufficient time has elapsed for the notching timing relay CLT to drop out. Opening of the make contacts CLTl results in interruption of the holding circuit for the notching relay 62. Thus, the relay -62 now drops out. Closure of the break contacts 62-1 and 62-3 and opening7 of the make contacts 62-2 and 62-4 have no immediate eiiiect on operation, since the contacts CLT1 now are open. Opening of the make contacts 62-5 interrupts the remaining holding circuit for the floor selection relay NOI, and thus the relay N01 drops out. The break contacts 62-6 close to parallel the already closed break contacts 61-7, thus having no effect on operation.

Dropout of the ioor selection relay N01 is accompanied by closure of its break contacts NO1-6 partially to reestablish the holding circuit for the transfer relay CTX (recalling that the break contacts NO2-6 in parallel with the contacts NOT-6 now are open). Opening of the make contacts NO1-7 has no eifect on operation, since the break contacts NO2-9 in series therewith now are open. Opening of the make contacts NO1-8 also has no eifect on operation, since the parallel make contacts 611-6 and 62-5 previously had opened to drop out the relay N01. The make contacts NOI-9 open, but the iloor selection relay NO2 remains energized and picked up through its holding circuit. The make contacts N01- 10 also open but have no effect on operation, since the make contacts NO2-12 in parallel therewith are closed at this time.

At 111:27 am. the one-half hour clock 1BH functions to open its make contacts 1BH1 without aifecting circuit operation and to close its break contacts IBHZ, which results in energization of the notching timing relay CLT. Closure of the make contacts MLTl has no effect on operation, since the contacts 1131-11 now are open. Thus, the floor selection relay NO2 remains picked up for the second assigned period of special service operation, that is, until 11:31 am., when the contacts of the one-half hour clock IBI-l again operate, resulting in the following sequence of operations: The break contacts 13H2 open to initiate the timing out of the notching timing relay CLT. The make contacts 1BH1 close to energize the notching relay 6i through the following circuit:

L1, 62--1, CLTl, 1BH1, 62-3, 61, R8, LZA

Pickup of the notching relay 61 is accompanied by the opening of its break contacts 61-1. Such opening,

however, has no eifect on operation, since the break contacts NO4-4 in parallel therewith are closed in the holding circuit of the special service master relay SLI-IO. The make contacts 61-2 close to establish the following short circuit around the notching relay 62:

Thus, the relay 62 remains dropped out. The make contacts 61-'3 close but have no effect on operation, since the break contacts NO2-9 are now open. Opening of the break contacts 5L-4 also has no effect on operation, since the oor selection relay NO2 remains picked up through its holding circuit. Closure of the make contacts 6ft-5 results in energization of the iloor selection relay NO3 through the now closed make contacts NO2 11. The make contacts 61-6 close to establish a holding circuit for the floor selection relay NO3 through the make contacts NO3-9, which close as a result of the pickup of the relay NO3. Closure of the contacts 61-6 has no eiect on the operation of the floor selection rclay NOl, however, since its make contacts N011# are open. Opening of the break contacts 61-7 has no eifect on operation, since the break contacts 62--6 in parallel therewith now are closed.

Opening of the break contacts NO3-t results in interruption of the holding circuit for the transfer relay CTX, since the break contacts NO2-'7 also are open at this time. Thus, such interruption would result in dropout of the relay CTX if the relay had been energized through its holding contacts CTXS. Opening of the break contacts NO3-5 has no effect on operation, since the break contacts NO4-S in parallel therewith are closed. Assuming that the make contacts CNRI are closed, opening of the break contacts NO3-45 results in dropout of the car assigning relay BSLHOB for the elevator car B. Opening of the break contacts NO37 has no immediate effect on operation, since the break contacts NO2-8 in series therewith are open, inasmuch as the floor selection relay NO2 at this time is picked up. Opening of the break contacts NO3-8 has no immediate effect on operation, since the break contacts NO2-9 in series therewith are also open.

As heretofore observed, closure of the make contacts NO3-9 resulted in the establishment of a holding circuit for the relay NO3 through the now closed make contacts 61-6. Closure of the make contacts NO3-10 has no immediate effect on operation, since the break contacts 61-4 in series therewith now are open. The make contacts NO3-11 also close to parallel the already closed make contacts NO2-12, thus having no effect on circuit operation at this time.

Assuming that the notching timing relay CLT now times out, opening of its make contacts CLTI removes the short circuit around the notching relay 62. The relay 62, therefore, is energized through the following circuit:

(Note that the notching relays 61 and 62 once again are energized in series.) The break contacts 62-1 and 62-3 open and the make contacts 62-2 and 62-4 close, but such operation has no immediate effect for the reason that the make contacts CLTi now are open, as aforementioned. The make contacts 62-5 close to parallel the now closed make contacts 61-6, thus having no effect on operation. The break contacts 62-6 open to interrupt the holding circuit for the oorselection relay NO2, since the break contacts 61-7 also are open at this time, and thus the relay NO2 drops out.

The break contacts NO2-7 close partially to reestablish the holding circuit for the transfer relay CTX. (It will be recalled that the break contacts NO3-4 in parallel with the contacts NO2-7 now are open.) The break contacts NO2-8 close, but such closure has no effect on operation, since the break contacts NO3-7 in series therewith now are open. rThus, the car assigning relay CSLHOB for the elevator car C remains dropped out. Closure of the break contacts NO29 also as no effect on operation, since the break contacts NO3-8 in series therewith now are open. Opening of the make contacts NO2-10 in the holding circuit of the floor selection relay NO2 has no immediate effect on operation, since the relay N O2 already is dropped out as a result of the opening of the parallel break contacts 61--7 and 62-6. The make contacts NO2-11 open, but such opening has no effect on operation, since the floor selection relay NO3 is maintained energized through its holding circuit. Opening of the make contacts NO2-12 also has no effect on operation, since the make contacts NO3-11 in parallel therewith now are closed.

At 11:33 am. the one-half hour clock lBH functions to open its make contacts 1BH1 without affecting operation and to close its break contacts 1BH2, as a result of which the notching timing relay CLT is energized. Closure of the make contacts CLT1, however, has no effect on operation, since the make contacts 1BH1 in series therewith now are open. Thus, the floor selection relay NO3 remains picked up during the third assigned period of special service operation.

At 11:35 am. the contacts 1BH2 of the one-half hour clock lBH open to initiate the timing out of the notching timing relay CLT. At this time the make contacts 1BH1 close to establish the following short circuit around the notching relay 61:

Thus, the relay 61 drops out.

Closure of the break contacts 61-1 in the holding circuit of the special service master relay SLHO has no effect on operation, since the break contacts NO4-4 in parallel therewith also are closed. Opening of the make contacts 61-2 has no immediate effect on operation, since the notching relay 62 remains picked up through the following holding circuit:

Opening of the make contacts 61-3 has no effect on operation, since the oor selection relay N01 is dropped out at this time. The break contacts 61-4 close to energize the fioor selection relay N04 through the now closed make contacts NO3-10. Opening of the make contacts 61-5 has no effect on operation, since the make contacts NO2-11 in series therewith already are open. The make contacts 61-6 open, but such opening has no effect on operation, since the make contacts 62-5 in parallel therewith still are closed. The break contacts 61-7 close to establish a holding circuit for the floor selection relay N04 through its now closed make contacts NO4-8.

Opening of the break contacts NO4-4 in the holding circuit of the special service master relay SLHO has no immediate effect on operation, since the break contacts 61--1 in parallel therewith now are closed. The break contacts NO4-5 open to interrupt the holding circuit of the transfer relay CTX, since the break contacts NO3-5 also are open at this time. Thus, if the relay CTX had been picked up through its holding contacts CTXS, the interruption of its holding circuit would result in its dropout. Opening of the break contacts NO4-6 results in dropout of the car assigning relay SLHOB for the elevator car A, assuming that the make contacts CNRl of the master car assigning relay CNR are in closed condition. Opening of the break contacts NO4-7 has no effect on operation, since the break contacts NO3-8 in series therewith still are open, inasmuch as the fioor selection relay NO3 is energized at this time. As heretofore noted, closure of the make contacts NULS, results in the establishment of a holding circuit for the relay N04 through the now closed break contacts 617. The make contacts NO49 close, but such closure has no immediate effect on operation, since the make contacts NO3-11 in parallel therewith still are closed.

It will be assumed that suiicient time has elapsed for the notching timing relay CLT to time out. Opening of the make contacts CLT1 interrupts the holding circuit for the notching relay 62, and thus the relay 62 drops out. Closure of the break contacts 62-1 and 62-3 and opening of the make contacts 62-2 and 62-4 have no effect on operation, since the contacts CLT1 now are open. The make contacts 62-5 open to interrupt the holding circuit for the floor selection relay NO3, and thus the relay NO3 drops out. Closure of the break contacts 62-6 has no effect on operation, since the break contacts 61-7 in parallel therewith already have closed as a result of the dropout of the notching relay 61.

Turning now to the contacts of the floor selection relay NO3, which has dropped out, the break contacts NO3-5 close partially to reestablish the holding circuit for the transfer relay CTX. (It will be recalled that the break contacts NO45 in parallel with the contacts NO3-5 now are open.) Assuming that the make contacts CNRI are closed, the break contacts NO3-6 and NO3-7 close to pick up the car assigning relays BSLHOB and CSLHOB for the elevator cars B and C, respectively. Closure of the break contacts NO3-8 has no effect on the operation, since the break contacts NO4-7 in series therewith now are open. Opening of the make contacts NO3-9 has no effect on operation, since it will be recalled that the holding circuit for the oor selection relay NO3 already has been interrupted as a result of the opening of the make contacts 61--6 and 62-5. The make contacts NO3-10 open7 but such opening has no eiect on operation, since the floor seelction relay N04 is maintained energized through its holding circuit. Opening of the make contacts NO3-11 also has no effect on operation7 since the make contacts NO49 in parallel therewith now are closed.

At 11:37 am. the make contacts IBI-l1 of the one-half hour clock open without affecting operation, and the break contacts IBHZ thereof close to energize the notching timing relay CLT. Closure of the make contacts CLT1, however, has no effect on operation, since the contacts lBHl now are open. Thus, the floor selection relay N04 remain picked up for the fourth assigned period of special service operation.

At 11:42 am. the contacts of the one-half hour clock 1BH again operate, resulting in the following sequence of operations: The break contacts 1BH2 open to start the timing out of the notching timing relay CLT. The make contacts IBI-l1 close to energize the notching relay 61 in the manner heretofore explained.

Pickup of the notching relay 61 results in the opening of its break contacts 61-1 to interrupt the holding circuit for the special service master relay SLHO. (It will be recalled that the make contacts 1BM1 of the master clock IBM and the break contacts NO4-4 both are open at this time.) Thus, the relay SLHO drops out to open its holding contacts SLHO3 and to open its make contacts SLI-104. Opening of the contacts SLHO4 removes the connection of the bus LZA to the bus L2 and thus interrupts direct current energization of the special service circuits connected to the bus L2A. As a result thereof, the notching relay 61 and the floor selection relay N04 both drop out to close thir break contacts 61-1 and NOi-t, respectively, partially to reestablish the holding circuit for the special service master relay SLHO. It will be observed, therefore, that special service operation has terminated and that its reinitiation awaits the closure of the master clock make contacts lBlVli on the following day, provided the manuallyoperable switch 103 is maintained in closed condition. Until that time, all four cars of the elevator system are transferred to and remain conditioned for normal offpeak operation.

The master load relay SWRX, is energized during special service operation through the break contacts CTX6 if at least one of the sets of make contacts SWR3,

23 BSWR3 or CSWR3 of the individual auxiliary load relays SWR, BSWR and `CSWR for the elevator cars A, B and C, respectively, closes to indicate that its associated elevator car is loaded and is about to leave `an assigned floor. Pickup of the relay SWRX results in closure of its make contacts, SWRXI partially to complete an energizing circuit `for the master car assigning relay CTX and SWRXZ to establish a holding circuit for the relay SWRX.

OFF-PEAK `OPERATION In order to assure a full understanding of the invention, certain typical operation of the elevator system now will be considered. First, it will be assumed that the entire system is conditioned for olf-peak operation, that the elevator cars all are parked at the lower terminal iioor and that a passenger enters the elevator car A at the lower terminal floor for the purpose of proceeding to the fifth floor.

The doors of the elevator cars may be of the manually-opened, spring-closed type or may be of conventional power-operated design. Upon entering the elevator car A, the passenger presses the car call push button c (FIG. 2) to energize the associated car call registering relay SCR. This relay closes its make contacts SCRI to establish a holding circuit around the push button. The relay also closes its make contacts SCRZ; but such closure has no effect on operation, since the make contacts SLHOI of the special service master relay SLHO are open, inasmuch as the elevator system is not conditioned for special service operation. Opening of the break contacts SCR3 (FIG. 4) results in deenergization of the call relay '78. Consequently, the break contacts 718-1 close to energize the dispatching relay 80N as follows:

SLHT'l--WSTZ--NOXS-SCCOIZ in parallel 78--1, SCCO10, 80N, L2

(Note that the first four sets of contacts in the foregoing circuit all are closed, since the car A is not conditioned for special service operation.)

Inasmuch as the relay `80N now is picked up, the contacts 80N1 (FIG. l) are closed. Since the elevator car A is at the lower terminal floor, it will be understood that the up preference relay W (FIG. l) is energized and picked up to close its make contacts Wil. It will be assumed also that the car A has remained at the lower terminal floor for a time sufficient to result in closure of the break contacts 7ttT1. Consequently, upon closure of the doors, the door relay DR closes its make contacts DR1 to complete the following circuit:

L1, '80ML 7T1, W1, Fl, ZI, U, M, DRI, L2

Upon energization, the up switch U closes its make contacts U1 to lrelease the elevator brake. Contacts U2 and U3 close to energize the generator field winding IHF with proper polarity for up travel of the elevator car. Contacts U4 closes to complete the following energizing circuit for the speed relay V:

LI, U4, I9, EI, V, L2

The speed relay closes its make contacts Vl to shunt the resistor R1 and thus conditions the elevator car for full speed operation. The speed relay V also opens its break contacts V2 (FIG. 3) without immediate effect on system operation.

Continuing with the operation of the up switch U, the energized up switch closes its make contacts U5 to establish a holding circuit around the contacts MINI, 70T1 and Wl. Break contacts U6 open to prevent energization therethrough of the down preference relay X.

The elevator car A now accelerates in the up direction for the purpose of carrying the passenger to the fifth lioor.

It will be recalled that the running relay M also was energized. As a result of its energization, the running relay closes its make contacts M1 :to prepare the relays G, E and F for subsequent energization. The make contacts M2 close without :affecting operation, since the break contacts II in parallel therewith remain closed at all times during off-peak operation of the car A. Make contacts M3 close to energize the non-interference relay 7 0T.

rThe non-interference relay opens its break contacts 70T1, 70T3 (FIG. 4) `and 70T4 and closes its make contacts 7tlT2 (FIG. 3) and 70T5 (FIG. 4), but such contact operations have no immediate effect on the operation of the system.

Under the assumed conditions, opening of the break contacts M4 (FIG. l) has no immediate effect on system operation. Referring to FIG. 2, the running relay M also closes its make contacts M5 and opens its break contacts M6. Such contact operations have no immediate effect on the operation of the system.

As the elevator car nears the fifth iioor, the brush kk (FIG. 4) engages the Contact segment kS, which is positioned above the now open break `contacts SCREI. Consequently, the call-above relay 78U is energized through the circuit:

L1, GCRS, 6DRZ, SURZ, kS, kk, W8, 78U, L2

The relay 78U closes its make contacts 78U1 (FIG. l). Under the assumed conditions, such closure has no effect on the operation of the system for the reason that the make contacts SLHOBl are open.

However, the approach of the elevator car A toward the fifth floor brings the brush bb (FIG. 2) into engagement with the contact segment b5 to energize the car cail stopping relay T through the circuit:

L1, SCRI, b5, bb, W4, T, M5 L2 The car call stopping relay closes its make contacts T1 (FIG. l) to energize through the contacts M1 the three relays G, E and F in parallel. The relay G closes its make contacts GI to establish a holding circuit around the contacts T1.

The energization of the inductor slowdown and stopping relays E and F prepares these relays for subsequent operation. As the elevator car A nears the fifth floor, the inductor slowdown relay E reaches the inductor plate UEP for the fifth floor, which completes a magnetic circuit resulting in the opening of the normally-closed contacts El. Such opening deenergizes the speed relay V. As a result of the deenergization of the speed relay V, make contacts V1 open to introduce the resistor R1 in series with the generator field winding MF. The resulting decrease in the output `of the generator slows the elevator car A to a landing speed. Closing of break contacts V2 (FIG. 3) has no immediate effect on the system.

As the elevator car A slowly approaches the tif-th iioor, the stopping relay F (FIG. l) reaches the inductor plate UFP for the fifth floor. This completes a magnetic circuit Which results in the opening of the normally-closed contacts Fl. In opening, the contacts F1 deenergize the up switch U and the running relay M.

The up switch U now opens its make contacts U1 to apply the elevator brake. Contacts U2 and U3 open to deenergize the generator field winding. Consequently, the elevator car now stops accurately at the fifth floor and its doors open to permit the departure of the passenger who registered the car call for the fth door. Opening of the make contacts U4 and U5 and closure of the break contacts U6 have no immediate effect on the operation of the system.

The running relay M opens its make contacts M1 to deenergize the relays G, E and F. The relay G opens its make contacts GI. Opening of the make contacts M2 has no immediate effect on system operation. Make contacts M3 open to deenergize the non-interference relay 70T. This relay now starts to time out. Closure of the break contacts M4 and opening of the make contacts M5 (FIG. 2) have no immediate eect on system operation.

Referring to FIG. 2, it should be noted that as the elevator car A approached the fth Hoor, the brush dd engaged the contact segment d5. When the running relay dropped out to close its break contacts M6, the following cancelling circuit was completed:

L1, SCRI, SCRN, d5, dd, W5, M6 L2 Consequently, the car call registering relay SCR is reset. As the car came to a stop, the brush bb passed slightly above the associated Contact segment b5.

The setting of the call registering relay SCR opens the make contacts SCRI and 5CR2 without affecting operation. In addition, the break contacts SCRS (FIG. 4) reclose to complete an energizing circuit for the call relay 78.

The call relay 78 as a result of its energization opens its break contacts 78-1 to drop out the dispatching relay 80N. As a result thereof, the make contacts SONI (FIG. 1) open. Consequently, when the non-interference relay 'MIT times out and recloses its break contacts 7lPTI, the up switch U and the running relay M cannot be energized until a call is registered from one of the floors or in the elevator car A to close the contacts 78-1 to reenergize the relay 80N.

Next it will be assumed that as the elevator car A was leaving the first floor in the. preceding example, a prospective passenger at the second floor registered an up oor call by operation of the up floor call push button 2U (FIG. 3). Such operation energizes the up floor call registering relay ZUR, which closes its contacts ZURI to establish a holding circuit around the push button. In addition, the registering relay opens its break contacts 2UR2 in the call circuit 30 (FIG. 4) and similar contacts, such as the contacts ZURS in the call circuit B for the elevator car B, for the remaining elevator cars in the bank. Since the registration of the car call for the fifth oor in the elevator car A already has deenergized the relay 78, opening of the contacts ZURZ has no effect thereon. However, the opening of the remaining contacts of the relay ZUR may affect the remaining elevator cars of the system. For example, the opening of the break contacts ZURS deenergizes the relay B78 for the car B and permits operation of this elevator car. The present discussion, however, will be confined yto the elevator car A.

As the elevator car A nears the second floor, the brush ee FIG. 3) engages the contact segment e2 to establish the circuit:

The energization of the floor call stopping relay S results in closure of the make contacts S1, (FIG. l) to energize the relays G, E and F. These cooperate to stop the elevator car A at the second `floor by a sequence which will be clear from the preceding discussion of the stopping of the elevator car at the fth floor. As the elevator car stops, the engagement of the brush (FIG. 3) with the contact segment f2 and the closure of the break contacts V2 complete the following cancelling circuit:

L1, 2UR1, 2URN, f2, W7, SLHoBs, vz., Lz

This resets the up iioor call registering relay. ZUR in the manner previously described. As a result of this resetting, the relay opens its contacts 2UR1 to remove the holding circuit around the push button 2U and recloses its break contacts 2UR2 (FIG. 4). Inasmuch as the contacts SCRS remain open, the reclosure of the contacts 2UR2 has no immediate effect on the system. However, the relay also recloses its break contacts 2UR3. If no other call is registered affecting the elevator car B, the reclosure of the contacts 2UR3 results in energization of the call relay B78.

Next it will be assumed that a prospective passenger at the fourth floor registers a down floor call by operation of the push button 4D (FIG. 3) after the elevator Gar A reached the fifth floor. The resultant energization of the down floor call registering relay 4DR closes the make contacts 4DR1 to establish a holding circuit around the push button. In addition, the registering relay opens its break contacts 4DR2 (FIG. 4) and similar contacts for the remaining cars, such as the contacts 4DR3` for the elevator car B. The opening of the break contacts 4DR2 deenergizes the call relay 78. This relay recloses its break contacts 78-1 to energize the dispatching relay 80N in the manner heretofore described. As a result, the make contacts 80N1 (FIG. 1) close.

It will be assumed that the elevator car A has remained at the fifth floor for time suiiicient to permit reclosure of the break contacts 70T1 of the non-interference relay. Consequently, upon closure of the doors associated with the car A, the up switch U and the running relay M are energized in the manner previously described to move the car upwardly to the upper terminal or sixth oor. As the elevator car A nears the upper terminal floor, the brush ee (FIG. 3) engages the contact segment e6 to complete the following energizing circuit:

L1, e6, ee, W6, S, SLHOB2, LZ

The relay S closes its make contacts S1 (FIG. l) to energize the relays G, E and F. These relays initiate a stopping operation of the elevator car A at the sixth floor in the manner which will be clear from the earlier discussion of the stopping of the elevator car at the fth floor. As it reaches the sixth oor, the elevator car A opens its limit switch 23 to deenergize the up preference relay W. Since this relay closes its break contacts W2 and since the break contacts U6 close as the car stops, an energizing circuit is completed for the down preference relay X through the limit switch 24. The deenergization of the up preference relay and the energization of the down preference relay condition the elevator car A for down travel.

As the car A approached the sixth floor, the brush kk (FIG. 4) engaged the contact segment k6 to reenergize the call-above relay 78U. Such energization, however, had no eifect on operation for reasons which will be apparent from the preceding discussion of the stopping of the elevator car at the fifth floor.

After the expiration of time sufficient to permit the non-interference relay 70T (FIG. 1) to time out, the break contacts 70T1 close to complete the following circuit:

L1, 80N1, 70T1, X1, F2, 22, D, M, DRl, L2

The relay D upon energization closes its make contacts D1 to release the elevator brake. Contacts D2 and D3 close to energize the generator field winding 171;` with proper polarity for down travel. Contacts D4 close to complete through the limit switch 20 and the contacts E2, an energizing circuit for the speed relay V. This relay closes its make contacts V1 to shunt the resistor R1. The elevator car A now accelerates to its full speed in the down direction.

Closure of the make contacts D5 establishes a holding circuit around the contacts 80N1, 70T1 and X1. Opening of the break contacts D6 has no immediate effect on the operation of the system. The running relay M upon energization operates its contacts in the manner previously described.

As the elevator car A nears the fourth floor, the brush gg (FIGS. 3) engages the contact segment g4 to complete the following energizing circuit:

L1, 4DR1, g4, gg, X6, S, SLHOB2, L2

As a result of its energization, the Hoor call stopping relay S closes its make contacts S1 (FIG. 1) to energize the relay G, E and F. The relay G closes its make contacts G1 to establish a holding circuit around the contacts S1. The continued movement of the elevator car A brings the inductor slowdown relay E adjacent the inductor plate DEP for the fourth floor and completes a magnetic circuit resulting in opening of the contacts EZ. Such opening results in deenergization of the speed relay V and this relay closes its break contacts V2. (FIG. 3) and opens its make contacts V1 (FIG. 1) to introduce the resistor R1 in series with the generator field winding.

The decrease in energization of the field winding slows the elevator car to a landing speed. The continued movement of the elevator car A at a slow speed brings the inductor stopping relay F adjacent the inductor plate DFP to open the contacts F2. Such opening deenergizes the down switch D and the running relay M. The down switch D opens its make contacts D1 to apply the elevator brake. Contacts D2 and D3 open to deenergize the generator field winding, and the elevator car stops accurately at the fourth floor. Opening of make contacts D4 and D5 and closure of break contacts D6 have no immediate effect on the operation of the system.

During the stopping operation, the brush hlt (FIG. 3) engages the contact segment h4 to complete the following cancelling circuit:

In addition, the brush jj engages the contact segment i4 to complete a second cancelling circuit as follows:

In resetting, the relay 4DR opens its holding contacts 4DR1. In addition, the relay recloses its break contacts 4DR2 (FIG. 4) and corresponding contacts in the call circuits for the remaining elevator cars of the system. if no other call is registered affecting the call circuit 30, the call relay 78 is energized and prevents further operation of the elevator car A.

It will be assumed that the passenger at the fourth iioor enters the elevator car and operates the push button 1c (FIG. 2) to initiate movement of the elevator car to the first floor. The resultant energization of the car call registering relay 1CR closes the holding contacts llCRl and the make contacts 1CR2. Closure of the contacts ICRZ has no immediate effect on system operation under the assumed conditions. Opening of the break contacts ICR'S (FIG. 4) deenergizes the call relay 78 and this relay closes its break contacts 78-1 to permit further movement of the elevator car. If sufficient time has elapsed for the non-interference relay 70T to drop out, the break contacts 70T1 (FIG. l) close. lf the doors `also are closed, an energizing circuit again is completed for the down switch D and running relay M through the now closed make contacts 80N1. These cooperate in the manner previously discussed to move the elevator car toward the first floor.

Opening of the make contacts 70T2 (FIG. 3) while the elevator car still was at the fourth floor had no immediate effect on operation for the reason that the brush jj remained in engagement with the contact segment f4 in the aforementioned fourth floor down floor call cancelling circuit until the elevator car A left the fourth floor.

:As the elevator car nears the first floor, the brush aa (FIG. 2) engages the contact segment a1 to complete an energizing circuit for the car call stopping relay T. This relay closes its make contacts T1 (FIG. l) to energize the relays G, E and F through the contacts M1. The energized relays E and F cooperate in the manner previously described to stop theelevator car at the first floor.

As it reaches the lower terminal floor, the elevator car A opens the lim-it switch 24 to deenergize the down preference relay X. This relay closes its break contacts X2 to complete an energizing circuit for the up preference reiay W as the elevator car stops at the lower terminal floor. The deenergization of the down preference relay X and the energization of the up preference relay W condition the elevator car A for up travel.

Pickup of the up preference relay W is accompanied by closure of its make contacts W5 (FIG. 2.). Thus, as

the elevator car stops, the brush dd engages the contact d1 to complete the following cancelling circuit:

L1, ICRI, lCRN, d1, dd, W5', M6, L2

In resetting, the relay 1CR opens its holding contacts 1CR1 and its make contacts 1CR2. The break contacts 1CR3 (FIG. 4) close to complete an energizing circuit for the call relay 78. The relay 78 opens its break contacts 78-1 to prevent further operation of the elevator car A untii a call is registered requiring such operation.

The elevator system as thus far described has provided what may be termed off-peak operation, that is, balanced service in the two directions of travel between the upper and lower terminal floors of the building.

SPECIAL SERVICE OPERATION It now will be assumed that the four elevator cars of the system A, B, C and yD are parked at the lower terminal iioor conditioned for up travel and that no call for service is registered in the system. Referring to FiG. 5, at 11:14 am. the make contacts 1BM1 of the master clock IBM close to energize the special service master relay SLHO, assuming that the manually-operable switch 103 is in closed condition. `Closure of the make contacts SLHOI and SLHOZ (FIG. 2) and similar contacts for the elevator car C has no immediate effect on operation, since under the assumed conditions no car call is registered in the system. Closure of the make contacts SIJHOS (FIG. 5) completes a holding circuit for the relay SLHO in order to maintain this relay energized after tne subsequent opening of the master clock contacts lIM. Closure of the make contacts SLI-104 connects the bus LZA to the bus L2 to provide direct-current energization for the circuits connected to the bus L2A.

At 11:15 am. the one-half hour clock contacts 1BH1 and IBHZ close and open, respectively, to effect the energization of the iioor selection relay N01 by a sequence of operations which will be apparent from the preceding discussion of FIG. 5.

Closure of the make contacts NOI-10 results in energization of the master car assigning relay CNR through the break contacts CTX6. The make contacts CNRI close to energize the car assigning relays SLHOB, BSLHOB and CSLiI-IOB for the elevator `cars A, B and C, respectively. The make contacts CNRZ close to initiate a timing operation of the timing relay CTA by permitting the capacitor CAI to charge therethrough, while the break contacts CNRS open to interrupt the discharge path of the capacitor CAI.

Referring now to FIG. 4, pickup of the car assigning relays is accompanied by closure of their respective make contacts SLHOBS, BSLHOBS and similar contacts for the elevator car C. Assuming that the noneinterference relay 70T (FIG. l) has timed out and recalling that no car call is registered for the elevator car A, the no car call relay SCCO (FIG. 4) is energized through the following circuit:

L1, 7iT3, 50-1, SCCO, SLHOBS, L2

Consequently, the relay `SCCO picks up to close its make contacts SCCO9 to establish a holding circuit for the relay.

inasmuch as the car A is at the first floor, the brush mm is not in engagement with any of its associated contact segments, and the assigned floor relay NOX, therefore, remains dropped out. The dispatching timing relay SLI'IT is energized through the now closed make contacts 70T5 and SLHOB. Opening of the make contacts SLI-W1 prevents energization therethrough of the dispatching relay SiiN. The load relay WST, through the closed load weighing switch WH, also is energized and picked up. Opening of the break contacts WS'TI and WST?. prevents energizaition therethrough of the auxiliary load relay SWR and the dispatching relay SSN, respectively.

Closure of the make contacts SLI-10139 connects the Y 29 signs 101 for energization from the buses L1 and L2. These signs indicate that the elevator car A is incapable of providing up service.

Returning to the contacts of the no car call relay SCCO, opening of the break contacts SCCOIO and SCCO12 prevents energization therethrough of the dispatching relay 80N. Since the reversing relay I is dropped out, closure of the make contacts 1SCCO11 completes the following energizing circuit for the dispatching relay:

L1, NOX3, J3, SCCO11, 80N, L2

Referring to FIG. 1 and assuming that the doors associated with the elevator car A are closed and conse quently that the door relay DR is picked up to close its make contacts DRI, closure of the make contacts 80N1 completes an energizing circuit for the up switch U and the running relay M. The elevator car A consequently accelerates to fullV speed in the up direction.

It will be observed by inspection of FIG. 1 that when the car assigning relay SLHOB for the elevator car A was energized, its make contacts SLHOBl closed to prepare the reversing relay I for subsequent energization.

By inspection of FIGS. 4 and l, it will be noted that the elevator car B also is accelerated to full speed in the up direction in a manner similar to that described for the car A. Although control circuits are not shown in FIGS. 4 and l for the elevator car C, it is assumed that the car C also is provided with circuits which cause its acceleration in the up direction at this time. Since the car D is not conditioned for special service operation, it remains at the rst floor.

In order to expedite service to the assigned oors during special service operation, assigned elevator cars preferably are prevented from answering registered up or down iloor calls. To this end, the break contacts SLHOBZ and SLHOB3 (FIG. 3) of the car assigning relay SLHOB opened when this relay was energized to prevent, respectively, energization of the oor call stopping relay S and cancellation of registered oor calls during up and down travel of the car A. Similar contacts, such as the contacts BSLHOB2 and BSLHOB3 for the car B, are provided in the tloor call registering relay circuits for the cars B and C. In order further to expedite service for assigned floors, it is desirable that the break contacts of the oor call registering relays in the call circuit 30 (FIG. 4) be shunted during up and down travel of the car A. To this end, the make contacts SLHOB4 through SLHOB7 of the car assigning relay SLHOB close to shunt the break contacts of the oor call registering relays for oors above the rst oor in the call circuit 30. As is shown, similar contacts also are provided for the elevator car/B, and the call circuit for the car C (not shown) also is provided with such contacts.

Referring now to FIG. 2 and confining the following discussion primarily to the elevator car A, it will be observed that the no car call relay SCCO, in picking up, opened its break contacts SCCOZ, SCCOS, SCCOS, and SCCO7 in `the car A car call registering circuits for the sixth, fth, fourth and third floors, respectively. Thus the pushbuttons for these oors are rendered ineffective for registering car calls as long as the relay SCCO remains energized. Opening of the break contacts SCCOS prevents the registration therethrough of car calls for the second lloor by oper-ation of the pushbutton 2C. However, since the break contacts W3 in parallel with the contacts SCCOS are open only when the up preference relay W is energized, i.e., when the car A is conditioned for up travel, car calls for the second oor may be registered when the car A is conditioned for down travel, inasmuch as the contacts W3 then are closed.

Closure of the make contacts SCCO4 and SCCO6 has no effect on operation at this time for the reason that the make contacts NO2-1 and NO3-1 respectively in series therewith are open. Since the floor selection relay Y 30 N01 is energized and its make contacts NOI-1, therefore, are closed, closure of the make contacts SCCO1 results in the registriation of what may be termed `an artificial car call for the sixth licor. Thus, the elevator car A proceeds upwardly in the manner previously described to answer such articial car call. (It will be noted that an artificial car call also is registed for the sixth floor for the car B by operation of the make contacts BSCCOI and NOI-2. Similar contacts (not shown) are provided in the sixth oor car call circuit for the car C.)

As the elevator car nears the sixth floor, the brush bb engages the contact segment b6 to complete the foillowing energizing circuit for the car call stopping relay T:

L1, SCCOI, NO1-1, b6, bb, W4, T, M5, LZ

Energization of the relay T results in closure of its make contacts T1 (FIG. 1) to energize the relays G, E and F. These cooperate to stop the elevator car A at the sixth floor by a sequence which will be clear from the preceding discussion.

As the elevator car stops, engagement of the brush cc with the contact segment c6 has no elect on operation for the reason that the make contacts 6CR1 are open, since the elevator car proceeded to the sixth floor in response to an articial car call, as aforementioned, rather than in response to the registration of a car call by the car call registering relay GCR.

As the car A neared the sixth floor, the brush kk (FIG. 4) engaged the contact segment k6 to complete the following energizing circuit for the ca1l-above relay 78U:

L1, k6, kk, WS, 78U, L2

As a result of this energization, the call above relay closed its make contacts 78U1 (FIG. 1) to complete an energizing circuit for the reversing relay J as follows:

L1, 78U1, SLHOBI, X3, I, L2

Opening of the break contacts I1 prevents subsequent energization therethrough of the up preference relay W. (It will be recalled that the limit switch 23 is opened upon arrival of the car A at the sixth floor to drop out the relay W in any event.) Closure of the make contacts J2 establishes a holding circuit for the relay I, which is Imaintained through the break contacts M4 as the elevator car stops at the sixth oor and the running relay M drops out, although the break contacts X3 in parallel with the contacts M4 subsequently open. Opening of the break contacts J3 (FIG. 4) prevents subsequent energization therethrough of the dispatching relay 80N. Closure of the make contacts J4 prepares the dispatching relay for subsequent energization therethrough as here inafter will be described.

Thus, the elevator car A now is stopped at the sixth floor conditioned for down travel, (It will be recalled that dropout of the up switch U (FIG. l) and up prefence relay W results in closure of the break contacts U6 and W2, respectively, to energize the down preference relay X through the limit switch 24.) At approximately the same time, the cars B and C arrive at the sixth floor and are conditioned for down travel by a sequence of operations which will be apparent from the preceding discussion of the arrival of the car A at the sixth floor. It will be noted that the cars A, B and C have traveled to the sixth floor in the absence of the registration of a floor call or a car call but in response to the registration of an artificial car call, as aforementioned. The stopping of the cars is accompanied by the opening of their respective doors to permit the entry therethrough of passengers desiring down elevator service.

It now will be assumed that sufficient time has elapsed for the non-interference relay 7tlT (FIG. 1) to drop out. Closure of the break contacts 76T1, opening of the make contacts 70TZ (FIG. 3) and closure of the break contacts 70T3 (FIG. 4) have no immediate effect on opera- 

